/** Map.ir reverse geocode (client; NEXT_PUBLIC_MAP_API_KEY). https://map.ir/reverse/no */

import { texts } from '@/texts'

const REVERSE_BASE = 'https://map.ir/reverse/no'
const v = texts.validation.map

/** Map.ir response address field only (official API) */
function pickAddressFromBody(data: unknown): string | null {
  if (!data || typeof data !== 'object') return null
  const address = (data as Record<string, unknown>).address

  if (typeof address === 'string' && address.trim()) return address.trim()

  return null
}

/** @returns `address` field or empty string; throws Error on failure */
export async function reverseGeocodeMapIr(lat: number, lng: number, apiKey: string): Promise<string> {
  if (!Number.isFinite(lat) || !Number.isFinite(lng)) {
    throw new Error(v.invalidCoords)
  }

  const key = apiKey.trim()

  if (!key) {
    throw new Error(v.mapKeyMissing)
  }

  const url = `${REVERSE_BASE}?lat=${encodeURIComponent(String(lat))}&lon=${encodeURIComponent(String(lng))}`

  let res: Response

  try {
    res = await fetch(url, {
      headers: {
        'Content-Type': 'application/json',
        'x-api-key': key,
      },
    })
  } catch {
    throw new Error(v.mapServiceError)
  }

  let data: unknown

  try {
    data = await res.json()
  } catch {
    throw new Error(v.mapInvalidResponse)
  }

  if (!res.ok) {
    throw new Error(v.mapAddressFailed)
  }

  const statusField = (data as { status?: unknown })?.status

  if (typeof statusField === 'number' && statusField >= 400) {
    throw new Error(v.mapAddressFailed)
  }

  const picked = pickAddressFromBody(data)

  return picked ?? ''
}